Question 155233
Frank can complete a job in 5 hours. Joe can do it in 8 hours. After Frank had worked for two hours, Joe was asked to help Frank complete the job. In how many hours after Joe has started will they complete the job?
:
let t = hrs that Joe and Frank worked together to complete the job
:
Let the completed job = 1
:
Frank will work a total of (t+2) hrs
:
A typical shared work equation:
{{{((t+2))/5}}} + {{{t/8}}} = 1
Get rid of the denominators by mult by 40, resultis:
8(t+2) + 5t = 40
8t + 16 + 5t = 40
13t = 40 - 16
t = {{{24/13}}}
t = 1.846 hrs they worked together to complete the job
:
:
Check solution on calc. (Frank worked 1.846 + 2)
(3.846/5) + 1.846/8) =
.769 + .231 = 1; confirms our solution